From the perlvar manpage: 

 $?      The status returned by the last pipe close, backtick (``) com-
           mand, successful call to wait() or waitpid(), or from the sys-
           tem() operator.  This is just the 16-bit status word returned
           by the wait() system call (or else is made up to look like it).
           Thus, the exit value of the subprocess is really ("$? >> 8"),
           and "$? & 127" gives which signal, if any, the process died
           from, and "$? & 128" reports whether there was a core dump.
            (Mnemonic: similar to sh and ksh.)

So you need to shift $? to get the return value of the command.
-derby

In reply to Re: gzip command always returns -1 by derby
in thread gzip command always returns -1 by jyoshv

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